352 research outputs found

    Heavy metal bioaccumulation by the important food plant, olea europaea L., in an ancient metalliferous polluted area of Cyprus

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    Aspects of the bioaccumulation of heavy metals are reviewed and possible evidence of homeostasis is highlighted. Examination and analysis of olive (Olea europaea L.) trees growing in close proximity to a copper dominated spoil tip dating from at least 2000 years BP, on the island of Cyprus, revealed both bioaccumulation and partitioning of copper, lead and zinc in various parts of the tree. A factor to quantify the degree of accumulation is illustrated and a possible seed protective mechanism suggested

    Measuring the activity of European and African Countries using Social Accounting Matrices

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    Economic models at the micro, meso and macro levels presuppose the existence of consistent databases that make it possible to quantify the activity of enterprises, sectors, regions, countries or continents. Such models can also be important aids in the policy decision process, since they permit the construction of scenarios resulting from the adoption of policy measures and the consequent changes that they introduce. When consistent with the United Nations System of National Accounts (SNA), the Social Accounting Matrix (SAM) can include all the nominal flows of the measured part of the economy, at the level of both production and the institutions, and therefore satisfies these requirements. Thus, in its numerical version, a SAM constitutes a database and provides a snapshot of the measured reality at a certain moment, whereas its possible algebraic versions, i.e. models that are based upon it, permit the construction of the above-mentioned scenarios. The possibility and usefulness of constructing SAMs for African countries consistent with the SNA will be examined and experimented. The SAM’s basic structure and consistency within the whole system will be studied, as well as any possible disaggregations, extensions, aggregates, indicators and balances that can be calculated. Other aspects beyond that basic structure will also be examined in order to show to what extent the SAM is capable of covering parts of the economy that are not covered by the SNA.info:eu-repo/semantics/publishedVersio

    Socio-economic studies with social accounting and sociodemographic matrices : an application to Portugal.

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    In looking for empirical evidence about the activity of countries, a proposal is made for studying (measuring and modelling) the activity of countries through the use of Social Accounting Matrices (SAMs) and Socio-Demographic Matrices (SDMs). SAMs and SDMs are presented as tools that have specific features for conducting studies in several different areas, as well as for supporting policy decision processes. Based on methodological principles that are derived mainly from the works of Richard Stone, emphasis is placed on the desirability of working in a matrix format, which includes not only people (SDM), but also, at the same time, activities, products, factors of production and institutions (SAM). This is considered to be a way of capturing the relevant network of linkages and the corresponding multiplier effects, which can be used for the subsequent modelling of the activity of the countries studied. A method will be proposed for the construction of these matrices. In the case of the SAMs, it is proposed that their design and construction should adopt, at least as their starting point, the latest version of the System of National Accounts (2008 SNA) and the corresponding results of its adoption/adaptation by different countries. The exposition of this proposal is accompanied by an example applied to Portugal.Financial support provided by FCT (Fundação para a CiĂȘncia e a Tecnologia)Portugal for the research and writing of this article, which forms part of the Strategic Project for 2011-13 (PEst- OE/EGE/UI0436/2011)

    Balanced Development

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    While economists and others might disagree over the most appropriate policies for stimulating development, there is at least some convergence of-views on objectives. The appropriate means may be in doubt, but the end that is commonly understood is to raise living standards on a sustainable basis

    Value co-creation in the animal healthcare sector

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    Domesticated animals form an important part of modern life, fulfilling roles as household companions, working animals or food producing livestock. Regardless of the position they realise within contemporary society,their day to day care is now complex and involves a range of animal healthcare practitioners in addition to the veterinary professional, termed paraprofessionals. The discerning nature of the modern client in combination with the developing roles of professionals within the sector has transformed market dynamics and highlighted the need for reflection on measures of service quality and its provision. This paper presents a conceptualisation of value co- creation within animal healthcare based on an analysis of sector stakeholders’ service experiences. Interviews with service providers and clients provide data for content analysis and highlight the dimensions of communication and integrated care as important components of service provision. Exploratory factor analysis of questionnaire data (n=271) following surveying of veterinarians and paraprofessionals,loaded onto seven latent factors, with strong dimensions of trust and communication identified. Disparity between veterinarian and client opinion was of interest and is worthy of further investigation,but results obtained support the application of value co-creation models to develop service quality within the UK animal healthcare sector

    Passive water control at the surface of a superhydrophobic lichen

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    Some lichens have a super-hydrophobic upper surface, which repels water drops, keeping the surface dry but probably preventing water uptake. Spore ejection requires water and is most efficient just after rainfall. This study was carried out to investigate how super-hydrophobic lichens manage water uptake and repellence at their fruiting bodies, or podetia. Drops of water were placed onto separate podetia of Cladonia chlorophaea and observed using optical microscopy and cryo-scanning-electron microscopy (cryo-SEM) techniques to determine the structure of podetia and to visualise their interaction with water droplets. SEM and optical microscopy studies revealed that the surface of the podetia was constructed in a three-level structural hierarchy. By cryo-SEM of water-glycerol droplets placed on the upper part of the podetium, pinning of the droplet to specific, hydrophilic spots (pycnidia/apothecia) was observed. The results suggest a mechanism for water uptake, which is highly sophisticated, using surface wettability to generate a passive response to different types of precipitation in a manner similar to the Namib Desert beetle. This mechanism is likely to be found in other organisms as it offers passive but selective water control

    Importancia de la biotecnologia vegetal en la uva apirena

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    Palladium catalysed coupling reactions of 6-O-tert-butyldimethylsilyl-1-bromocodeine and 6-O-tert-butyldimethylsilyl-3-trifluoromethylsulfonylmorphine allow a range of substituted analogues of codeine in the 1-position and morphine in the 3-position to be efficiently and selectively prepared
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